Batteries are commonly used in daily life, such as a remote controller and a toy car. Most of existing batteries are disposable batteries. These batteries are discarded after running out of power. If these batteries are used for a long time, they are higher in cost. These discarded batteries easily pollute the environment. Accordingly, a rechargeable battery arises. The rechargeable battery may be recharged after running out of power due to its rechargeable characteristic, which may greatly reduce the cost of using the batteries. The existing rechargeable battery is unreliable and unreasonable in structure. Generally, with respect to the existing rechargeable battery, a charging circuit board is disposed at a positive electrode position of the battery. It is necessary for two nickel strips to connect with a positive electrode and a negative electrode of a cell and a head portion of the cell to be sharpened. The battery is wrapped with a tubular steel sleeve as a whole. Such a structure has a desoldering risk due to the adoption of the nickel strips for connection. An opening of the steel sleeve has burrs, which easily damage an outer film of the battery. There is a mark in a joint between the steel sleeve and a cell, resulting in unevenness.